Fix some Qt editor crashes

Fix use-after-delete on proplists by item view and crash on recursive execution of message processing.

src/editor/C4ConsoleQtObjectListViewer.cpp

@@ -58,6 +58,14 @@ void C4ConsoleQtObjectListModel::Invalidate()
 	emit layoutChanged();
 }
 
+void C4ConsoleQtObjectListModel::OnItemRemoved(C4PropList *p)
+{
+	for (auto idx : this->persistentIndexList())
+		if (idx.internalPointer() == p)
+			this->changePersistentIndex(idx, QModelIndex());
+	Invalidate();
+}
+
 void C4ConsoleQtObjectListModel::SetSelection(class C4EditCursorSelection &rSelection)
 {
 	// Reflect selection change in view
@@ -132,12 +140,12 @@ QVariant C4ConsoleQtObjectListModel::data(const QModelIndex & index, int role) c
 	else if (role == Qt::ForegroundRole)
 	{
 		// Deleted proplist?
-		if (!data) return clr_deleted;
+		if (!data) return QVariant(clr_deleted);
 		// Object?
 		C4Object *obj = data->GetObject();
 		if (obj) return QVariant(); // default
 		// Effect
-		return clr_effect;
+		return QVariant(clr_effect);
 	}
 	// Nothing to show
 	return QVariant();

src/editor/C4ConsoleQtObjectListViewer.h

@@ -42,6 +42,7 @@ public:
 
 	// Refresh object list on next redraw
 	void Invalidate();
+	void OnItemRemoved(C4PropList *p);
 
 	// Callback from EditCursor when selection was changed e.g. from viewport
 	void SetSelection(class C4EditCursorSelection &rSelection);

src/editor/C4ConsoleQtState.cpp

@@ -150,6 +150,22 @@ void C4ConsoleViewportWidget::closeEvent(QCloseEvent * event)
 }
 
 
+/* Recursion check to avoid some crashing Qt re-entry */
+
+class ExecRecursionCheck
+{
+	static int counter;
+public:
+	ExecRecursionCheck() { ++counter; }
+	~ExecRecursionCheck() { --counter; }
+
+	bool IsRecursion() const { return counter > 1; }
+};
+
+int ExecRecursionCheck::counter = 0;
+
+
+
 /* Console main window */
 
 C4ConsoleQtMainWindow::C4ConsoleQtMainWindow(C4AbstractApp *app, C4ConsoleGUIState *state)
@@ -339,6 +355,8 @@ void C4ConsoleGUIState::AddToolbarSpacer(int space)
 	
 bool C4ConsoleGUIState::CreateConsoleWindow(C4AbstractApp *app)
 {
+	// No Qt main loop execution during console creation
+	ExecRecursionCheck no_qt_recursion;
 	// Basic Qt+Main window setup from .ui file
 	int fake_argc = 0;
 	application.reset(new QApplication(fake_argc, NULL));
@@ -396,22 +414,28 @@ bool C4ConsoleGUIState::CreateConsoleWindow(C4AbstractApp *app)
 	return true;
 }
 
-void C4ConsoleGUIState::Execute()
+void C4ConsoleGUIState::Execute(bool redraw_only)
 {
+	// Avoid recursion in message processing; it's causing random crashes
+	ExecRecursionCheck recursion_check;
+	if (recursion_check.IsRecursion()) return;
 	// Qt window message handling and object cleanup
 	if (application)
 	{
-		application->processEvents();
-		application->sendPostedEvents(0, QEvent::DeferredDelete);
+		if (redraw_only)
+		{
+			// process only non-critical events
+			application->processEvents(QEventLoop::ExcludeUserInputEvents);
+		}
+		else
+		{
+			// process everything
+			application->processEvents();
+			application->sendPostedEvents(0, QEvent::DeferredDelete);
+		}
 	}
 }
 
-void C4ConsoleGUIState::Redraw()
-{
-	// process only non-critical events
-	if (application) application->processEvents(QEventLoop::ExcludeUserInputEvents);
-}
-
 // Set action pressed/checked and enabled states
 void C4ConsoleGUIState::UpdateActionStates()
 {

src/editor/C4ConsoleQtState.h

@@ -182,8 +182,8 @@ public:
 
 	void AddToolbarSpacer(int space);
 	bool CreateConsoleWindow(C4AbstractApp *app);
-	void Execute();
-	void Redraw();
+	void Execute(bool redraw_only=false);
+	void Redraw() { Execute(true); }
 	void UpdateActionStates();
 	void UpdateMatTex();
 	void UpdateBackMatTex();

src/editor/C4ObjectListDlg.cpp

@@ -21,6 +21,7 @@
 #include <C4Console.h>
 #include <C4Object.h>
 #include <C4GameObjects.h>
+#include <C4Effect.h>
 
 
 #ifdef USE_GTK
@@ -865,7 +866,7 @@ void C4ObjectListDlg::Update(C4EditCursorSelection &rSelection)
 // Could do some crazy fine-grained updates. But updating is cheap enough...
 void C4ObjectListDlg::OnObjectRemove(C4ObjectList * pList, C4ObjectLink * pLnk)
 {
-	if (view_model) view_model->Invalidate();
+	if (view_model) view_model->OnItemRemoved(pLnk->Obj);
 }
 
 void C4ObjectListDlg::OnObjectAdded(C4ObjectList * pList, C4ObjectLink * pLnk)
@@ -890,7 +891,7 @@ void C4ObjectListDlg::OnEffectAdded(C4Effect *fx)
 
 void C4ObjectListDlg::OnEffectRemoved(C4Effect *fx)
 {
-	if (view_model) view_model->Invalidate();
+	if (view_model) view_model->OnItemRemoved(fx);
 }